// exercise 1
sequenceDiagram
    autonumber
    actor U as User
    participant WS as Web Server
    participant SD as Salt Database
    participant PD as Password Database

    U->>WS: Access Web Server
    WS->>U: Promt for Username
    U->>WS: Provide Username
    WS->>U: Prompt for Password
    U->>WS: Provide Password

    WS->>SD: Send Username
    SD->>SD: Search for Salt
    SD-->>WS: Return Salt

    WS->>WS: Encrypt provided password using Salt

    WS->>PD: Send Username
    PD->>PD: Search for stored Encrypted Password
    PD-->>WS: Return stored Encrypted Password

    WS->>WS: Compare Encrypted Passwords

    alt Passwords Match
        WS->>U: Display Success Page
    else Passwords Do Not Match
        WS->>U: Display Failure

    end


stateDiagram-v2
    [*] --> Idle

    note right of Idle : Waiting for requests


    Idle --> Searching : Recieve Username
    note right of Searching: Database looks up record

    Searching --> Replying : Salt Found
    note right of Replying: Sending data back

    Replying --> Idle : Salt Sent


// exercise 2
stateDiagram-v2
    [*] --> Idle: Power On

    state "Idle\n(entry: LED Off)\n(do: Display Time)" as Idle
    state "Alarm Setting" as Setting
    state "Alarming\n(entry: Start Flash)\n(do: Beep)" as Alarming
    state "Snooze\n(do: Display Time)" as Snooze


    Idle --> Setting: press set button
    Setting --> Idle: press save button

    Idle --> Alarming: alarm time reached / Turn LED On

    Alarming --> Idle: press stop button / Stop Beeping, Stop Flashing

    Alarming --> Snooze : press snooze button / Stop Flashing

    Snooze --> Alarming: after 5 mins / Send E-mail


// exercise 3

graph TD
    Mobile[Mobile Device]
    Web[Web Browser]

    subgraph "E-Store Application"
        Acc[Accounting Function]
        Cat[Catalogue Function]
        Ord[Ordering Function]
        Pri[Pricing Function]
        Inv[Inventory Function]
    end

    DB_Acc[(Accounting DB)]
    DB_Cat[(Catalogue DB)]
    DB_Ord[(Ordering DB)]
    DB_Pri[(Pricing DB)]
    DB_Inv[(Inventory DB)]

    Mobile -.-> Acc
    Mobile -.-> Cat
    Mobile -.-> Ord
    Web -.-> Acc
    Web -.-> Cat
    Web -.-> Ord

    Ord --> |Output is Input| Pri
    Pri --> |Output is Input| Inv

    Acc --- DB_Acc
    Cat --- DB_Cat
    Ord --- DB_Ord
    Pri --- DB_Pri
    Inv --- DB_Inv